Solve for y?

Question

1/3x+y=4 


And 


3x+1/5y=7

 

 

Answer 1

Given equations : (1/3)x+y=4  and  3x+(1/5)y=7

3x+(1/5)y=7

15x+y = 35          -------------- (1)

(1/3)x+y=4

x+3y=12

x = 12 - 3y           -------------- (2)

Substitute equation (2) in equation (1)

15x+y = 35

15( 12 - 3y ) + y = 35

180 - 45y + y = 35

180 - 35 = 45y - y

44y = 145

y = 3.295

Solution : y = 3.295